Chord playing attachment for stringed musical instruments



Dec. 5, 1961 R. w. BRIMHALL 3,011,380

CHORD PLAYING ATTACHMENT FOR STRINGED MUSICAL INSTRUMENTS Filed Jan. 20, 1959 3 Sheets-Sheet 1 59 40 INVENTOR Dec. 5, 1961 R. w. BRIMHALL CHORD PLAYING ATTACHMENT FOR STRINGED MUSICAL INSTRUMENTS Filed Jan. 20, 1959 3 Sheets-Sheet 2 5 6 4 5 2 2 0/ PO 4 5 a m T 3 6 4 3 a 0 4 5 6 "N 7 V \b 7 Q G a n ufl w wit 4 C 5 ,0 q a .1 a 5 H u 6 L U %-NZ 5MW O H A! 6 h. 6 Mul. w 4 wall a G 2u@ I E? a \o @3 4 e f a a q} s. 3 4 r. u a Q a Dec. 5, 1961 R. w. BRIMHALL I 3,011,380

CHORD PLAYING ATTACHMENT FOR STRINGED MUSICAL INSTRUMENTS Filed Jan. 20, 1959 5 Sheets-Sheet 3 I Illl m! ;Ta I a ll JIIIIIIIIIIW I: m E; z: 33

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Eura/v W EQ/MMQLL AGENT 3,011,380 CHORD PLAYING ATTACHMENT FOR STRINGED MUSICAL INSTRUMENTS Rulon W. Brimhall, 636 W. 8th St., Mesa, Ariz. Filed Jan. 20, 1959, Ser. No. 787,903 6 Claims. (Cl. 84-317) This invention relates to a chord playing attachment of extremely simple construction adapted to be mounted on stringed musical instruments having fretted keyboards, such as guitars and ukuleles or similar instruments having no frets, said attachment having a manually rotatable eiement operable for selectively moving string depressing elements into positions to depress the instrument strings whereby desired chords may be accurately played by strumming or picking the instrument strings. Furthermore, the present patent application is a continuation in part of my copending patent application for a chord playing attachment for stringed musical instruments, Serial No. 689,615, filed October 11, 1957, now abandoned.

More particularly, it is an object of the present invention to provide a chord playing attachment including rotatably mounted members supporting the string depressing elements and which are rotatable simultaneously by manipulation of a manually rotatable element for positioning string depressing elements of the different rotatable members in positions to contact the instrument strings.

Another object of the invention is to provide a chord playing attachment wherein the string depressing elements may be accurately operated by the manually rotatable ele ment in the form of a dial equipped with indicia means and regulated by a click latch, to retain said dial in predetermined selected positions of rotation and with the rotatable members which support the string depressing elements correctly indexed for playinga selected chord.

Another object of the invention is to provide a chord playing attachment for stringed musical instruments which may readily be attached to a variety of guitars having a variety of dimensions without alteration of the guitar or the attachment. 1

Another object of the invention is to provide a chord playing attachment for stringed musical instruments wherein the housing of the attachment is supported on a nut fitted over the conventional string engaging nut whereby the spacing of the strings correspond with the string engaging fingers of the attachment and whereby the attachment is properly located laterally, longitudinally and vertically with respect to the strings of the guitar or other musical instrument.

Another object of the invention is to provide a chord playing attachment having a dial provided with a playing position disc which is rotatably mounted with respect to a key indicating dial whereby playing positions may be eadily set up in various keys.

Another object of the invention is to provide a chord playing attachment for stringed musical instruments which is particularly adapted to be molded and thereby constructed of plastic or other similar materials.

Still a further object of the invention is to provide a chord playing device which is extremely compact so that it may be equipped with sufiicient string depressing elements to play as many as twelve chords so that a complete harmonization, as for example in the keys of C, G, and D, with their relative minor keys, may be played utilizing the attachment.

Various other objects and advantages of the invention wi l hereinafter become more fully apparent from the following description of the drawings, illustrating various embodiments thereof, and wherein:

FIGURE 1 is a fragmentary plan view of the neck and States Patent Ofiice 3,911,380 Patented Dec. 5, 1961 head of a stringed musical instrument and showing the chord playing attachment applied thereto;

FIGURE 2 is a fragmentary side elevational view thereof looking from left to right of FIGURE 1, and on an enlarged scale;

FIGURE 3 is an enlarged longitudinal sectional view taken substantially along a plane as indicated by the line 3-3 of FIGURE 1;

FIGURES 4, 5 and 6 are cross sectional views taken substantially along planes as indicated by the lines 44, 5-5 and 66, respectively, of FIGURE 1;

FIGURE 7 is a fragmentary view of a modified form of the chord playing attachment;

FIGURE 8 is a fragmentary sectional view thereof, taken substantially along a plane as indicated by the line 8-8 of FIGURE 7;

FIGURE 9 is a fragmentary top or plan view of the neck of the guitar showing a modified form of my chord playing attachment for stringed musical instruments in accordance with the present invention and showing parts and portions thereof broken away and in section to amplify the illustration;

. FIGURE 10 is a fragmentary side elevational view of the neck of a guitar and showing my chord playing attachment for stringed musical instruments in connection therewith and further illustrating portions broken away in section to amplify the illustration;

FIGURE ll is a sectional view taken from the line 11 ll of FIG. 10 showing portions broken away and in section to amplify the illustration;

FIGURE I2 isa fragmentary sectional view taken from the line l212 of FIGURE 10, and;

FIGURE 13 is a fragmentary sectional view taken from the line 13I3 of FIGURE ll.

Referring more specifically to the drawings and first with reference to FIGURES l to 6, the chord playing attachment in its entirety is designated generally 10 and includes an elongated rectangular frame, designated generally 11, having substantially parallel sides 12 and 13 connected by substantially parallel ends 14 and 15.

The sides 12 and 13 are provided with aligned openings 16, two of which are shown in FIGURE 4 to provide journals for three shafts 17, I8 and 19 which extend therethrough. Rollers 20, 21 and 22 are mounted on said shafts 17, 13 and 19, respectively, between said side walls 12 and 13 and are keyed to the shafts, as seen at 23 in FIGURE 4, for rotation of the rollers with said shafts and within the frame 11. Corresponding gears 24 are fixed to the shafts 17, 18 and 19 between rollers thereof and the side wall 12 and said gears are disposed in meshing engagement with one another so that the shafts and rollers will revolve simultaneously and at uniform speeds.v

As best seen in FIGURE 3, the rollers 20, 21 and 22 are preferably of octagon shape in cross section so that the periphery of each roller has eight flat surfaces or faces 25 from certain of which faces 25 of each roller project string depressing elements 26. Said string depressing elements 26 preferably comprise staples the ends of which are anchored in the rollers so that the staples project perpendicularly from the faces 25 thereof. Certain of the string engaging elements, designated 26a, as illustrated in FIGURE 1, are longer than the elements 26, in a direction longitudinally of the rollers, to engage two or more strings whereas the remaining elements 26 are of a length and are so positioned with respect to the rollers as to engage a single string of a musical instrument, as

will hereinafter be more fully described, and as is clearly illustrated in FIGURES l and 4.

The intermediate shaft 18 has a threaded extension 27 at one end thereof which engages a central opening 23 of a dial 2?, as seen in FIGURE 4. A nut 30, which is threaded on the shaft portion 27, cooperates with a collar 31 of said shaft for clamping the dial 29 immovably thereon. The dial 2? is spaced outwardly from the side wall 12. As seen in FIGURE 2, the dial 29 has eight projections BZextending outwardly from the periphery thereof and which are disposed in circumferentially spaced relation to one another. The dial 29 is also provided with a ring of openings 33 which are disposed in radial alignment with the projections 32. Each projection 32, on the outer side of the dial 259, is provided with indicia and a pointer, as seen at 34 in FIGURE 2, to designate a chord. Said pointers 34 of the dial 2% function with a fixed pointer 35 on the frame side '12 to pro'videindexing means for the rollers 20, 21, and 22. Y A' leaf spring 36 has one end secured by a fastening 36a to the wall 12. The free end of the spring 36 is provided on its outer side with a knob 37 which has a rounded outer face 38. Said free end of the spring and the knob 37 are disposed behind a portion of the dial 29., and with the knob portion 38 positioned to engage in the dial openings 33 to releasably latch the dial in eight different positions of rotation, in each of which positions one of the dial pointers 34 is in alignment with the stationary index pointer 35. The rounded knob face 38 functions as a cam surface for camming the knob out of engagement with the openings 33 as the dial 29 is revolved, the leaf spring 36 yieldably urging the knob 37 toward the rear side of said dial. g

The, chord playing attachment it} is adapted to be detachably mounted on the neck 39 of a stringed musical From the'foregoing it will be readily apparent that the chord playing attachment it may be readily operated by manually rotating the dial 29 for positioning selected string depressing elements 26 and/ or 26a in downwardly extending positions relative to the rollers thereof for depressing selected ones of the strings 44 and adjacent 'various ones of the frets 42 for accurately producing desired chords when the strings are strumrned or picked in a conventional manner. The meshing gears 24 will cause the three rollers to revolve simultaneously and at uniform speeds when the dial 29 is turned. It will also be apparent that each projection 32 of the dial 29 is related to one face-or surface 25 of each of the three rollers 2%, 21 and 22, so that when the indexing pointer of said projection 32 aligns with the pointer 35, said three faces 25 will be disposed in lowermost positions in r opposed substantially parallel relation to the finger board 41 and so that-the string depressing elements 26 of 26a projecting from said surfaces 25 will be positioned to I i of the rollers and wherein two rollers 63 and 6 are instrument and on the head 40 thereof. The neck 39 is shown provided on its upper side with the usual finger board 41 having the transversely disposed frets 42. A nut or divider 43 is mounted between the head 40 and the adjacent end of thefinger board 41 for holding the strings 44 properly spaced from one another.

A bail 45 engages around the underside of the neck 39 and has end portions disposed on the inner sides of the'side walls 12 and 13 adjacent the end wall 14 and which are provided with slots 46, as best seen in FIGURE 5, for accommodating the bolts of nut and bolt fastenings 47 which extend therethrough and through said side walls 12. and 13. A metal strap member 48 is secured to the inner side of each of the bail ends by fastenings 49 and has a slot 56 registering with the slot 46 through which the fastening 47 extends. Portions of the fastenings '49 bear against the frame sides 12 and 13 so that when the fastenings 47 are tightened the bail ends will be adjustably clamped immovably to the frame 11. The straps 48 have inturncd lower ends 51 which bear on side edge portions of the finger board 41 so that one end of the frame is thus adjustably supported at a desired elevation above the finger board. A setscrew 52 is threaded through a. threaded opening 53 in the intermediate portion of the bail 45 and a knob 54 of a cushioning material is mounted on the inner end of the setscrew 52 and bear against the underside of the neck 39. By tightening the setscrew 52 the neck will be clamped between the strap ends 51 and knob 54 to secure the bail 45 immovably on said neck.

One side 55 of an angle bracket is secured by fastenings 56 tothe outer side of the end wall 15 and the other lower side 57 of said bracket extends outwardly from the frame 11. A bar 58 hasdepending pads 59 which rest upon the upper surface of the head 40, adjacent the nut 43. Bolts of nut and bolt fastenings 60' extend upwardly through end portions of the bar 58 and through said bracket side 57. Spacers 61 are mounted on the fastenings 60 between the bar 58 and bracket side 57. Said parts 55 through 61 cooperate to support the other end of the frame 11 at a proper elevation above the finger board. The bar 58 is detachably secured on the head 40 by an elastic loop member 62 which engages as the elements 26 and 260;.

shown and which are supported for rotation in the same manner "as the rollers 20, 21 and 22. However, the rollers 63 and 64 are not of multisided cross sectional shaped and are not provided with staple elements such Rather, the rollers 63 and 64 are preferably cast with integral projections 65 and 66 which are formed integral with and project from the peripheries of said rollers and which provide string de-' pressing elements to function in the same manner and for the same purpose as the elementsze and 26a. The

string depressing elements 65 and 66 may be of different lengths, longitudinally of the rollers for engaging one ormore strings 44.

In the modification of the present invention as shown in FIGURE 9 of the drawings, a steel nut 70 is placed over the conventional string engaging nut 72 in order to raise the strings 74 of the musical instrument substantially above the finger board frets'75.

The steel nut 70 is an inverted substantially channel shaped member which is probably made of steel or other hard material suitable for retaining the musical instrument strings 74 in certain spaced relationship to each other at a location near the string tightening keys of the instrument which are not shown. The nut 70 is provided with grooves 75 wherein the strings are bedded and these strings are drawn taut over the finger board as shown best in FIGURE 10 of the drawings.

The device of the present invention comprises abox shaped frame 78 wherein a plurality of rollers Stl, 32 and 84 are rotatably mounted. These rollers are provided with extending fingers 85, 86 and 88, respectively, which are arranged in patterns intended to coincide with desired chords when the rollers are rotated into positions wherein the fingers engage the strings of the musical instrument.

The box shaped frame 78 is provided with opposite side walls 90 and 92 wherein openings 94 and 96 form bearings which rotatably support annular bearing portions $8 and Hit) of the rollers. These rollers Sit, 82 and '84 may be molded of plastic material or may be made of any other suitable material as desired. The fingers as shown in- FIGURE 10 of the drawings extend radially from the roller as and are provided with curved extremities 102. arranged smoothly to engage the strings when the roller 8% is rotated relative to the strings;

Located inside the box shaped frame 78 and adjacent to the inner side of the wall 94 thereof are spur gears 104, 106 and 108 which are fixed to the rollers 80, 82 and 84, respectively. These gears are all provided with geared teeth and mesh with'each other forming a gear train.

The hub of the gear 186 is provided with a central bore 110 wherein a stub shaft 111 is fixed and which extends outwardly ot the frame side wall 99. Carried by the stub shaft 111 is a dial wheel 112 having key designations 114 on its outer side and spherical indents 116on its inner side adjacent to the wall 98 of the box shaped frame 78. A spherical detent member 118 is spring loaded to engage the spherical recesses 116 and is provided with a shank 120 reciprocally mounted in abore 122 centrally of the gear 188. A spring 124 surrounds the shank 120 and engages the end of the gear 188 while the opposite end of the spring 124 engages the spherical detent member 118 thereby spring loading it into contact with the recesses 116 and the dial wheel 112. Thus, the dial wheel 112 is positively indexed in certain positions corresponding to the locations of the fingers 85, 86 and 88 on the rollers 80, 82 and 84 whereby predetermined chords may be played when the fingers are engaged with the musical instrument strings in accordance with the location of certain of the designations 114 with respect to the detent 116.

The dial wheel 112 is provided with a stub bearing 126 on which is rotatably mounted a key indexing disc 128. This key indexing disc 128 is provided with numerical designations 130 and a pointer 132 directed toward one of the designations 114. Thus the pointer 132 is directed toward a certain key inwhich accompaniment is desired then the accompaniment is played according to the numerical designations 130. Thus the disc 128 serves to predetermine the key in which chords may be played upon a musical instrument to which the chord playing attachment is connected. The disc 128 is held in a desired position by a thumb screw 134 having a screw threaded shank 136 engaged in a central portion of the dial wheel 112. A washer 138 is engaged by the thumb screw 134 in order to clamp the disc 128 in contiguous relation with the outer side of the dial wheel 112.

It will be seen that when the dial wheel 112 is rotated the spur gears 104, 186, 108 cause concurrent rotation of the rollers 80, 82 and 84 thereby carrying their respective fingers, 85, 86 and 88 into contact with the strings 74 of the musical instrument. Due to the elevation of the strings maintained by the steel nut 70 the strings do not contact the conventional frets 76 of the musical instrument and in this manner the device of the present invention controls the vibrating lengths of the strings 74.

The steel nut 70 precisely locates the elevation of the rollers 80, 82 and 84 with respect to the strings 74 and also locates one end of the frame 78 laterally with respect to the strings 74. Furthermore, the nut 78 also locates the device of the present invention longitudinally of the strings in order that the fingers of the rollers 88, 82 and 84 engage the strings at proper locations substantially corresponding with locations of conventional keyboard frets.

As shown in the drawings the frame 78 is provided with an extending nut engaging bar 148 which rests on opposite ends of the steel nut 70. This bar 140 is provided with a ledge 142 at one end and a ledge 144 at its opposite end which rests upon the steel nut 70 at its upper side near its opposite ends. The bar 146 is provided with a tunnel 146 located between the ledges 144 and 142 and this tunnel clears the strings 74 sufiiciently to permit vibrating freedom thereof beyond the point at which they contact the steel nut 78.

Opposite ends of the nut 79 are engaged by ledges 148 and 150 of the bar 148 in order to locate the frame 78 laterally with respect to the strings 74 while the ledges 142 and 144 locate the same vertically with respect to the nut 78 as shown in the drawings.

As shown in FIGURE 13 the bar is provided with a ledge 152 which engages the side of the steel nut 78 which faces the bridge of the musical instrument. One

of these ledges 152 is adjacent each of the ledges 148 and 158 as shown in FIGURE 11 of the drawings whereby the frame 78 of the present invention may be located longitudinally of the instrument finger board and instrument strings 74 so that the fingers 85, 86 and 88 of the rollers will correspond to normal fret locations on the musical instrument.

The box shaped frame 78 is provided with an end wall 154 which interconnects the side walls 98 and 92 a' jacent to the bar 146. This bar 148 is provided with a body portion 156 which is secured inside the wall 154 and in engagement with ribs 158 on the inner sides of the wells 98 and 92. The bar 141-8 is thus held in position in the frame 78 and may be cemented into the frame 78 when and if desired. Such construction may be particularly desirable when all of the parts are made of plastic as shown.

It will be appreciated by those skilled in the art that the use of the steel nut 70 and the bar 149 permits the device of the present invention to be secured precisely in position on guitars having varying dimensions of the neck string spacing and other features. The steel nut maintains precise spacing of the instrument strings 74 with respect to spacing of the fingers on the rollers 80, 82 and 84. Thus, a guitar or other instrument is readily adapted to the fixed dimensions of the device of the present in vention.

It will be understood that some guitars have a narrow neck with close-string spacing while other guitars have a wider neck with relatively wider spacing of the strings. This situation has caused great difficulty in the adaptation of any chord playing attachment to a great variety of musical instruments. Applicant has solved these problems with the use of the present invention wherein the steel nut maintains the spacing of the strings precisely with respect to the spacing of the fingers on the rollers and further the bar 140 precisely locates the elevation of the rollers and fingers with respect to the strings while also holding the device in a proper chord playing position longitudinally of the instrument substantially to coincide with normal fret positions of the instrument. The bar 148 is held securely in engagement with the nut 78 by means of a U-shaped clamp 159 having hook shaped ends 160 and 162 engaging channels 164 and 166 in ledges 170 and 172 projecting from the sides 90 and 92 of the frame 78. Screw threaded in the middle portion of the clamp member 159 is a screw 174 engaging a soft nut 176 which bears against the lower side of the instrument neck 178. The thumb screw 174 when tightened clamps the frame 78 securely in place wherein the bar 140 firmly engages the steel nut 70 as hereinbefore described. The opposite end of the frame 78 is held by a clamp member 180 similar to the clamp member 159 and this clamp member 180 holds a bar 182 firmly engaged with the finger board 184 of the instrument.

The bar 182 is secured in the frame in a similar manner to the body 156 of the bar 140. However, the bar 182 is provided with feet 186 and 188 which engage the top of the finger board 184 between the strings 74. The clarnp180 when tightened in a fashion similar to that of the clamp member 159 causes firm frictional engagement of the legs 186 and 188 with the string board of the instrument thereby locating the end 190 of the chord playing attachment precisely with respect to the strings 74 of the musical instrument.

The modification of the present invention as shown in FlGURES 9 to 13 of the drawings renders the chord playing attachment of the invention very simple and easy to install on a variety of musical instruments having dimensional differences. Additionally, the modified structure positively locates the chord playing attachment on the instrument by means of the string engaging nut 7d which is placed over the conventional nut 72. This arrang'e'xn ent also raises the strings above the frets of the a string board so that only nominal pressure of the roller efined by the appended claims.

I claim:

the function or scope of the invention as hereinafter.

' 1. In' a chord playing attachment for stringed musical instruments the combination of: a box shaped frame. I

having substantially parallel sides; a plurality of axially parallel rollers revolublymounted therein between said sides and disposedto have their axes at right angles to the strings of a musical instrument; meshed spur gears on said rollcrs inwardly of one side of said box shaped frame for synchronizing the rotation of all of them; spaced finge'rson said rollers disposed to engage said strings; a position indicating dial connected to one of said rollers for manual rotary actuation of all of them.

2. In a chord playing attachment for stringed musical instruments the combination of: a box shaped frame having substantially parallel sides; a plurality of axially parallel rollers revolubly mounted therein between said sides and disposed to have their axes at right angles to the strings of a musical instrument; meshed spur gears on said rollers inwardly of one side of said box shaped frame for synchronizing the rotation of all of them;

spaced fingers on said rollers disposed to engage said strings; aposition indicating dial connected to one of' said rollers for manual rotaryactuation of all of them; a key indicating disc rotatably mounted on said position indicating dial. i

3; 1n a chord playinlgattachment for stringed musical instruments the combination of: a box shaped frame having substantially parallel sides; a plurality of axially parallel rollers revolubly mounted therein between said sides and'disposed to have their axes at right angles to the strings of a musical instrument; meshed spur gears on said rollers inwardly of one side of said box shaped frame for synchronizing the rotation of all of them; spaced fingers on said rollersdisposed to engage said strings; a position'indicatingdial connected to one of said rollers for manual rotary actuation of all of them, said spur gearsconnected to adjacent ends of said rollers; and aside member of said frame outwardly of said spur gears. I

4. In a chord playing attachment for stringed musical instruments the combination of: a box shaped frame having substantially parallel sides; a plurality of axially parallel rollers revolubly mounted therein between said sides and disposed to have their axes at right angles to the strings of a musical instrument; meshed spur gears on said' rollers inwardly of one side of said box shaped frame for synchronizing the rotation of all of them; spaced fingers on said rollers disposed to engage said strings; a position indicating dialconnected to one of said rollers for manual rotary actuation of all of them; a channel shaped string supporting nut disposed to be positioned over a conventional musical instrument string s,011,aso

&

engaging nut; a bar on one end of said frame having ledge portions engaging opposite ends, the top andone side of said channel shaped nut for locating the forward end of said frame laterally, vertically and longitudinally relative to said strings;

5. In a chord playing attachment for stringed musical instruments the combinations of: a box shaped frame .having substantially parallel sides; a plurality of axially parallel rollers revolubly mounted therein between said sides and disposed to have their axes at right angles to the strings of a musical instrument; meshed spur gears on said rollers inwardly of one side of said box shaped frame for synchronizing the rotation of all of them;'

spaced fingers'on said rollers disposed to engage said strings; a position. indicating fdial connected to one of said rollers for manual rotary actuation of all of'them;

a channel shaped string supporting nut disposed to be V positioned over a conventional musical instrument string engaging nut; a bar on one end of said frame having ledge portions engaging opposite ends, the top and one side of said channel shaped nut for locating the forward end of said frame laterally, vertically and longitudinally relative to said strings, said ledge portions engaging opposite ends of said channel shaped nut and also the normally I upper and side'portions thereof at said opposite ends.

6. In a chord playing attachment for stringed musical l instruments the combination of: a box shaped frame a channel shaped string supporting nut disposed to be positioned over a conventional musical instrument string engaging nut; a bar on one end of said frame having ledge portions engaging opposite ends, the top and one side of said channel shaped nut for locating the forward end of said frame laterally, vertically and longitudinally relative to said strings, said ledge portions engaging opposite ends of said channel shaped nut and also the normally upper and sideportions thereof at saidopposite ends; legs extending from said frame and disposed to be posttioned between said strings, said legs having ends disposed to engage a finger board adjacent said strings; and a clamp member engaging said frame and disposed to exi tend around a musical instrument neck for holding said bar down on said channel shaped nut and for holding the ends of said legs firmly engaged with the normally upper surface of said fingerboard.

References Cited the file of this patent UNITED STATES PATENTS McBride Apr. 20, 1943 

